Re: [PATCH 2/5] arm64: dts: qcom: sc8180x: Add Microsoft Surface Pro X

[Val Packett <val@packett.cool>]

On 11/15/26 12:16 AM, Haipeng Lin wrote:
> On 11/4/26 2:04 AM, Val Packett wrote:
>> From: Maximilian Luz <luzmaximilian@gmail.com>
>>
>> Introduce a device tree for the Surface Pro X tablet in all 3 variants
>> (SQ1 with cellular, SQ1 Wi-Fi only, SQ2 with cellular).
> [...]
>
> I believe there is also a Wi-Fi only SQ2 variant. Looking at the WoA
> drivers for 8180_CAS (Caspar, Wi-Fi only)
> https://github.com/WOA-Project/Qualcomm-Reference-Drivers/tree/master/Surface/8180_CAS/200.0.31.0
Huuuh, okay..
> This variant is the only that has both SurfaceSMF_SQ1.cab and
> SurfaceSMF_SQ2.cab. Only 8180_CAS MPSS INF maps the no-modem subsystem
> ID (SUBSYS_MSNM8180 -> qcmpss8180_nm.mbn), the 8180_CAR (Carina) only
> lists the cellular MSWW/MSJP/MSCN IDs.
>
> My SQ2 Wi-Fi boots with the caspar dts in this patch fine but the
> gold cluster is pinned at SQ1's top clocks because the 3.072 / 3.1488
> GHz OPPs are only in carina.dts.
>
>> diff --git a/arch/arm64/boot/dts/qcom/sc8180x-microsoft-carina.dts b/arch/arm64/boot/dts/qcom/sc8180x-microsoft-carina.dts
>> new file mode 100644
>> index 000000000000..5d155c69907a
>> --- /dev/null
>> +++ b/arch/arm64/boot/dts/qcom/sc8180x-microsoft-carina.dts
>> @@ -0,0 +1,50 @@
>> +// SPDX-License-Identifier: BSD-3-Clause
>> +
>> +/dts-v1/;
>> +
>> +#include "sc8180x-microsoft-surface-pro-x.dtsi"
>> +
>> +/ {
>> +	model = "Microsoft Surface Pro X (SQ2)";
>> +	compatible = "microsoft,carina", "qcom,sc8180x";
>> +};
>> +
>> +&cpu4_opp_table {
>> +	opp-3072000000 {
>> +		opp-hz = /bits/ 64 <3072000000>;
>> +		opp-peak-kBps = <8368000 51609600>;
>> +	};
>> +
>> +	opp-3148800000 {
>> +		opp-hz = /bits/ 64 <3148800000>;
>> +		opp-peak-kBps = <8368000 51609600>;
>> +	};
>> +};
>> +
> [...]
>
> Would it make sense to move opp-3072000000 and opp-3148800000 into the
> shared sc8180x-microsoft-surface-pro-x.dtsi? qcom-cpufreq-hw disables
> all DT OPPs first and only re-enables freqs present in the hardware LUT
> so this would work for SQ1 and caspar.dtb will cover both the SQ1 and
> SQ2 Wi-Fi models out of the box and carina.dts won't need its own
> &cpu4_opp_table override.

I'm pretty sure mine *did* complain very loudly about having these OPPs 
and might've even had broken scaling.

I'll retest again, if it works I'll move it to the shared dtsi (or even 
the SoC's?)

>> diff --git a/arch/arm64/boot/dts/qcom/sc8180x-microsoft-surface-pro-x.dtsi b/arch/arm64/boot/dts/qcom/sc8180x-microsoft-surface-pro-x.dtsi
>> new file mode 100644
>> index 000000000000..17fb01c6b164
>> --- /dev/null
>> +++ b/arch/arm64/boot/dts/qcom/sc8180x-microsoft-surface-pro-x.dtsi
> [...]
>> +&smb2351_2 {
>> +	status = "disabled";
>> +};
>> +
>> +&smb2351_a {
>> +	status = "disabled";
>> +};
> Confirmed on hardware that labeling pmic@2 and pmic@a in
> sc8180x-pmics.dtsi fixes the dtc build failure here.
Yeahh, forgot to include, will be in v2
> [...]> +&uart13 {
>> +	pinctrl-0 = <&uart13_state>;
>> +	pinctrl-names = "default";
>> +
>> +	status = "okay";
> [...]
>
> On linux-surface, ad1bb617a15a from Maximilian Luz had
>
> &qupv3_id_2 {
>    status = "okay";
> };
>
> Would it be helpful to add here? I confirmed on hardware that adding it
> allows uart13 (WCN3998 Bluetooth) and uart15 (SAM EC) to populate and
> probe properly.
Of course; it should've been the _2 in the first place but I made a 
mistake during last-minute cleanup and left out the wrong ones…
> Thanks,
> Haipeng


BTW, please send me the output of `sudo fwupdtool hwids`, these are 
needed to add support to dtbloader/systemd-stub/stubble DT auto-selection.

(If anyone with the cellular variants reads this: you too :))


Thanks,

~val